1. Field of the Invention
The present invention relates to a condenser system which is forced-air cooled and includes a plurality of heat exchange elements, preferably roof-shaped heat exchange elements having a steam distribution line which forms the ridge of the elements. Cooling air is supplied to the heat exchange elements by fans. The heat exchange elements are disposed directly next to a turbine housing, and are disposed parallel to one another.
2. Description of the Prior Art
In the recent past there has been a recognizable trend to continuously larger power plant outputs with direct condenser systems. Steam exhaust from the turbines is conveyed via large-volume conduits directly into forced-air cooled heat exchange elements, where such steam exhaust is condensed. The cooling air is delivered by fans which are customarily disposed on the intake air side below the heat exchange elements. To avoid long paths, which result in a reduction of the condensation temperature and hence a reduction of the efficiency of the condenser system, the heat exchange elements are disposed directly next to the turbine housing.
Condenser systems are known according to which, to reduce the space required, the heat exchange elements are roof-shaped, with the ridge thereof being formed by the steam distribution line. Since the length of a heat exchange element is limited for thermohydraulic reasons, the roof-shaped heat exchange elements are preferably disposed parallel to the front of the turbine housing, so that despite the limited length of the heat exchange elements, the overall condenser system can be constructed as deep as desired.
Especially, when, for reasons of space, a plurality of power plant units are arranged in a row next to one another, unfavorable in-flow conditions result with regard to the air flow for the inwardly disposed heat exchange elements of the condenser system. Due to the turbine housing, as well as the adjacent heat exchange elements, virtually three of the four sides of the heat exchange elements are blocked off as in-flow cross-sectional areas for the cooling air. The air velocity on the remaining free side is therefore very high, since all of the fans must be supplied with fresh or intake air via this cross-sectional area.
Experiments have shown that the recirculation of warm air, i.e. of cooling air which has been warmed up by absorbing heat as the cooling air flows through the heat exchange elements, also increases as the velocity of the intake air supplied to the fans increases. In this case, the fans draw in an air mixture which has a higher temperature than does the atmospheric air. The immediate result is a reduction of the cooling capacity, and hence a reduction of the efficiency of the condenser system. The recirculation rate of the air increases especially when there is encountered a cross wind, the direction of which extends opposite to the in-flow direction of the cooling air, because the cross wind deflects the warm air which leaves the heat exchange elements in the direction toward the in-flowing intake air.
An object of the present invention is to provide a forced-air cooled condenser system of the aforementioned general type according to which the recirculation of warm exhaust air is considerably reduced, even under unfavorable wind conditions, without having to install expensive wind or air guiding apparatus in order to achieve this avoidance of recirculation of warm exhaust air.